In computing, firmware is software that is embedded in a hardware device, that allows reading and executing the software, but does not allow modification, e.g., writing or deleting data by an end user.

Examples of firmware include:

• the BIOS found in personal computers.
• Open Firmware, used in Apple Macintosh computers
• the computer program in a read-only memory (ROM) integrated circuit chip. A hardware configuration is usually used to represent the software.
• the erasable programmable read-only memory (EPROM) chip, which program may be modified by special external hardware, but not by an application program.

A well known specific example is Source: from Federal Standard 1037C and from MIL-STD-188\n